Some methods for making upper and lower molds are publicly known. One of them comprises the steps of holding a match-plate between cope and drag flasks, inserting upper and lower squeezing means into the respective openings of the cope and drag flasks, which openings are opposite to the match-plate, thereby defining upper and lower molding spaces, then supplying molding sand to the upper and lower molding spaces, and causing the upper and lower squeezing means to move forward to the match-plate for squeezing the molding sand in the upper and lower molding spaces so as to make flaskless upper and lower molds (see International Publication No. WO 2005/058528 A1).